President Rodrigo Duterte vowed on Tuesday to file an impeachment complaint at the House of Representatives against Ombudsman Conchita Carpio Morales whose office has been investigating the Chief Executive's alleged hidden wealth.

In an interview with reporters in Malacanang, Duterte expressed belief Morales is part of the conspiracy to oust him.

"We will file an impeachment case against her and I would tend to believe that she was part of the conspiracy, this fabricated papers," he said, apparently referring to the records of bank transactions of the president and his family, which the Office of the Ombudsman allegedly obtained from the Anti-Money Laundering Council.

AMLC has denied providing the Ombudsman of Duterte's bank transactions, which allegedly contain millions or even billions of money.

Duterte said the documents allegedly on the hand of the Ombudsman were fabricated.

Asked what could be the ground for impeaching Morales, he said it would be "selective justice" and "use of falsified documents."

Under the Constitution, the six grounds for impeachment are culpable violation of the Constitution, treason, bribery, graft and corruption, other high crimes and betrayal of public trust.

Duterte accused that the documents allegedly in possession of the Ombudsman allegedly came from the alleged mistress of Senator Antonio Trillanes IV, his staunch critic.

He identified Trillanes' mistress as "Abad," who used to head the AMLC.

He was apparently referring to former AMLC executive director Julia Bacay-Abad, who quit from the post in February this year.

Duterte has been denying he has huge amounts of money. He insisted that his lifetime savings would not go beyond P40 million. This was much lower from the P27.4 million that he declared in his statement of assets, liabilities and net worth as of end December 2016. Celerina Monte/DMS